<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <!--
        block  块元素
        inline 行内元素
        inline-block 块元素 可以放在一行
        none 不见了
    -->
    <style>
    div{
        width: 100px;
        height: 100px;
        border: 1px solid red;
        display: block;
    }
    span{
        width: 100px;
        height: 100px;
        border: 1px solid red;
        display: inline-block;
    }
    </style>
</head>
<body>
<div>div块元素</div>
<span>span 行内元素</span>
</body>
</html>